The invention relates to a touch contact switch with a plane contact arrangement consisting of a fixed contact and a movable counter contact contacting the fixed contact upon operation of the touch contact switch, and of a cover of elastic, rubber-like material vaulting the contact arrangement and comprising an operating member which is fixed elastically at a distance from the contact arrangement and passes this distance by a clearly recognizable stroke H upon operation of the touch contact switch by the force P and which effects the contacting of the contact arrangement by a partial surface of its inner side after the stroke has been completed.
Such touch contact switches, arranged separately or multiply beside each other forming a keyboard, are, in addition, usually surrounded by a casing. Sometimes a key cap is located above the operating member. The cover may be formed as a mat, especially with keyboards. Touch contact switches are used within printed circuits, for example, or with input keyboards for electronic systems such as calculators or manual transmitters of remote control devices. Touch contact switches have an installed, clearly recognizable height of stroke, in general between 1 and 4 mm.
Such a touch contact switch with a snap effect in the stroke is known from West German laid open application No. 33 40 575. FIG. 5 and FIG. 6 thereof show ribs which limit the further stroke after the contacting has taken place.
U.S. Pat. No. 4,390,765, too, shows a touch contact switch with snap effect. In particular, it proposes means for increasing the key stroke length until the desired snap effect has been achieved. A considerable part of the total stroke remains as rest stroke until the contacting.
In order to achieve a contact with satisfying feel, according to West German laid open application No. 32 22 747, the inclination of the movable contact is to be avoided by supporting members. The supporting members are to be of smaller height than than the movable contact. They become effective only after the contacting has taken place.
A disadvantage of the known touch contact switches is that they cause contact to take place after an installed restoring force has already been overcome. Thus, there is the danger of malfunctions due to subjects resting on the touch contact switch, for example, and battery energy is consumed unnecessarily.